Fluid-pressure motor



Gv. H. GROTH P LUID PRESSURE MOTOR. APPLICATION man JULY 3,1916.

Patented 00t.19,192o.

3 SHEEIS-SHEET l.

` WMM,

e. H, Gamm FLUID PRESSURE MQTOR. APPLICATION. FILED JULY 3)' 1916.

1,355,962. K' Ptented Oct. 19, 1920.

3 SHEETSTSHEET 2.

E [fst S tag e guaine/1,

G. H. GROTH.

FLUID PRESSURE MOTOR.

APPLICATION FILED IULY 3. I9I6.

1,355,296@ Tamm @@I. 19,1920;

3 SHEETS-SHEET 3.

GEonGE H. Gnorn,

ement orner..

OF DAYTON, OHIO.

ELUrnrnEssUEE Moron.

To all whom it may concern:

Beit known that I, GEORGE -I-I. GRo'rH,

' citizen of the United States, residing vat fication.

Dayton, in the county of Montgomery and State of Ohio, have invented.certain new and useful Improvements in Fluid-Pressure Motors, of whichMy linvention relates. to pneumatics and more particularly to a vmotivesupply system for pneumatic or other fluid pressure motors. 1

rIhe object of the invention is to simplify the construction as well asthe means .and mode -of operation of such systems` whereby they will notlonly bev cheapened in construction, but 'will be more eilicient `inuse, positive and uniform in operation, substantially automatic, andunlikely to get out of repair. A further object of the invention isstoprovide an improved vmethod or system .of compounding the expansiveforce or energy of the actuating media whereby a higher dei grec ofeiiciency andra greater degree of` available energy is afforded.v

With thevabove primary and other inci-I- dental objects in View, as-willmore fully appear in the specification, the invention consists of thefeatures of construction, the parts and combinations thereof, and themode of operation, or their equivalents, a's herein@v after describedand set forth in the c1aims.` Referring to the drawings, Figure l is a/diagrammatic view of the assembled apparatus and connections-comprisingthe system forming the subject matter hereof'. Figs. 2 to 5, inclusive,are diagrammatic views illustrating successive stages in the cycle ofoperations. Fig. 6 is a detail view Oof the valve operating means.

Like parts are indicated by similar char-.p acters of referencethroughout the vseveral views.

It is believed that this invention is'based irst: upon the generallyrecognized law of physics that any degree of intrinsic or stored energyis capable of reproducing itself or.

creating a like condition less losses due to friction `and leakage; andsecond: to Mariottes law, viz., The temperature remaining the same, thevolume of a given quantity of gas varies inversely as the pressure. Inother words, the product ofpressure and volume is constant.

Under the first mentioned rule, given a container of compressed airorgas having a volume of two cubic feet and a pressure of Specication ofLetters Patent.

the following is a speci- Patented oet. 19, 1920.

Application lied'July 3, 1916. Serial No. 107,458.

eighty pounds per square inch, the intrinsic or stored energy or thecapacity for Work of such body of compressed air or-gas is suiii' cientto effect the charging of a second contamer of equal volume to an equalpressure less those losses due to friction and leakage.

Under Mariottes law before stated, the

same container having a volume of two cubic feet of air or gas u nderpressure ofeighty pounds .per square inch if permitted to expand withoutloss into a container having a v volume of four cubic'feet, the pressurewill have been decreased to one half or forty pounds per square inch.Multiplying the volume by the pressure in each instance, viz: 2 f80=160and 4X40:160, it will be found "that one body is equal to the other orthat the inherent energy or capacity for work is the same in bothinstances. In applying this principle t`o the present invention, theappli-l cant inlieu o f employing a container of double capacity employsa second container of equal capacity into which the air or gas isallowed to expand from the first container when contained in the singlecontainer.

`As stated in Mariottes law, this condition is. dependent upon thetemperature remaining the same. In other words, under iso- `thermalexpansion or when the absorption of heat is suiiicient to compensate forthe fall oftemperature due to expansion to maintain the air at eventemperature under the variy ation of pressure.

In the present instance an isothermal condition is effected by jacketingor insulating the containers to retain or prevent the disbursement ofthe heat resulting from high compression and ,alternating the high andlow pressures vin the 'respective containers with rapidity whereby theair is expanded from higher to'lower pressure into a containerpreviously heated by the high pressure until the pressure in the twocontainers isl charge and the charge at high pressure is received in thecontainer previously cooled by the expansion of the air thereinto atlower pressure, the alternation or reversal occurring with such rapidityas to tend-t0 .equalize the temperature and to approach a uniform degreeof temperature or isothermal condition. i

With theaforementioned basic principles in mind, it is thought that thefollowing description of the invention forming the subject matter hereofmay be readily understood.

As illustrated in the assembly diagram Fig. 1, the operating parts andconnections are divided into two series hereinafter referred to as thehigh pressure and low pressure sides. These high and low pressure.series or sides alternate at each succeeding stage of operation. Thelow pressure side or series during one stage of operation becomes thehigh pressure side or series during the neXt stage of operation and viceversa. Likewise, the variable pressure containers or tanks of each sideor series vhereinafter referred to alternate between high pressure andlow pressure in addition to the alternation of high and low pressureloe-- tween the respective sides or series.

The volumes or capacities of the several tanks or containers andthepressures herein mentioned have been arbitrarily assumed merely for thepurpose of illustration, It will be understood that the invention is notlimited to any particular relation of pressures or of capacity hereinmentioned but that boththe volume and pressure-may be varied to meetdierent conditions of use. The required degree of pressures and therelative proportions of the containers or the volumeto meet differentconditions may be ascertained by mathematical calculation. y

Referring to thedrawings, 1 is the main reservoir or supply tank towhich air is supplied under pressure by the compressor 2. The compressormay be driven by any suitable or convenient means. The fluid pressuremotor to be operated comprises the high pressure cylinder 3 and lowpressure cylinders iP-4. The actuating media is supplied to the motorfrom the main reservoir or supply tank 1 through intermediate auxiliaryor variable pressure tanks and valved conduits or connections.

As before mentioned, the auxiliary tanks and connections are dividedinto high and low pressure sides or series. These high and low pressuresides and series are identical one with the other and a description ofone will suiiice for both except for such in-i cidental references asmay b e made in explaining the operation.v To aid iny identifyingcorresponding partsof thev respective sides or series, the sam'ereference characters will be used. Those peitaining to the low pressureside or series, as shown in Fig. l, are distinguished from the oppositeside by the addition of prime marks.

The air under compression is carried from the compressor 2 to the maintank or reservoir 1 through the inlet conduit 5 having therein acheckvalve 6; The main reservoir or tank 1 is of comparatively largesize in proportion to the capacity of the auxiliary or variable pressuretanks hereinafter mentioned. The admission of a charge of air into theinitial auxiliaryor variable I pressure tank from the main supply tankwill thus cause but a slight lowering of the pressure in the main tank.In the diagram Fig. l the capacity of the main reservoir or tank hasbeen assumed as four hundred cubic feet and its maximum pressure aseighty and four tenths pounds per square inch whereby theinitialauxiliary or variable pressure container or tank will be supplied at theassumed working high pressure of eighty pounds per square inch. Eightypounds per square inch will therefore be the minimum supply tankpressure. After each charge is delivered to the auxiliary tank thecompressor restores the main tank pressure from eighty to eighty andfour tenths (80.4) pounds pressure.

In order that the compressor ,2 may not be compelled to operate idlyagainst an excessive highpressure as would be the case if a safety valveas ordinarily used was applied to the tank, there has been provided arelief conduit 7 leading to a cylindei 8 within which is located apiston S) operated against the tension of a spring l() by thepressure'within the main tank or reservoir l.

piston 9 to open a relief port 1Q in the compresser conduit 5. Theconstruction is such that when the tank or reservoir l has been restoredto its maximum or operating pressure the valve ll will be operated toopen the port l2 thereby permitting the compressor 2 to operate idly.

The high or low pressure sides or series of the apparatus comprise twoauxiliary or variable pressure tanks or containers A and l and A and l,respectively, lwhich containers or tanks are suitably acketedv orinsulated to retain and prevent the loss yof heat. The auxiliary orvariable pressure Jranks are connected by sundry conduits hereafterseparately referred to with two series of valves a., l), e, d, e, f', y,h, i, and series of valves n., c, (l, c, 7', y, t, i, and 'lhesevalvesare arranged in groups and are operated in proper time and sequence byvalve operating mechanism controlled by the motor. In Fig. 6 there hasbeen shown valve operating means comprising a cam drum c having thereona plurality of cam surfaces 1/ engaging and reciprocating in turn thestems e of the several valves a, c, (Z, &c. The cam surfaces 1/ are sopositioned in relation one with the other as to secure the proper timingof the valve. The first group ot valves comprising the valves l l a, 7),a and b are connected by the conduits 13 and 13 and the common conduit14 with the main or supply tank l.

l l I group of valves c, d, c and ai are cony Connected to the piston 9is a valve 11 adapted upon movement of the The second vneeted by theconduits and 15.' and the common conduit 16 with the intake port of thehigh pressure cylinder 3. The third group' of valves e, f, e and f areconnected pressure cylinders 4 4. An exhaust -conduit 21 leads fromV theexhaust ports .of the low pressureylinders 'L1- 4 to atmosphere. Y

Located in the auxiliary or variable presture tanks'Aand B are pistonheads 22 and 23 rigidly connected one with the other by an intermediatepiston rod 24. Similar piston heads are mounted in the auxiliary tanksof the opposite series. These piston heads are free to move in unisonthroughout the length lof their respective tanks or containers.Leading'to the inner or adjacent ends of the auxiliary tanks A, B, and Aand B are inlets or ybreathing tubes 25 and 25', each having therein acheck valve 26 and 26 adapted to admit air at atmospheric pressure tothe tank but preventing the escape of air therefrom. x 'i Assuming thatthe main tank 1 has been supplied with air under pressure to its maxi'mum operating pressure of eighty and four tenths pounds, and that theinitial auxiliary or variable pressure tank A is likewise charged withair at a pressure of eighty pounds, Kthe apparatus is in initialcondition for operation. This condition is indicated as the first stage,Fig. 2. lIt will be understoodl that the valves a to jl and a to y" areopened and closed in proper sequence. and for proper intervals of timeby -suitable cam drums or shafts operated by the motor. In starting theapparatus it will be necessary to operate the motor by hand or' byexternal means through one cycle o f-operation in order to admitv the'air under-pressure to the several cylinders to 'cause' the motor' tooperate the valves `through succeeding cycles of operation.

The valves c and e being opened by the valve'operatingmechanism, the airunder high .pressure will How from the auxiliary. 'j tank A through theconduit 27 to the valve e, then. through the conduits 15 and 16 to thehigh pressure cylinder 3 and will be exhausted fromthe high pressurecylinder 3 through the conduits 18 and 17 to the valve e and thenthrough the condui'tv28 to the inner end ofthe auxiliary tank B, the in-`ternal pressure, of which is at normal at- ,mospheric pressure. Theair. will cont1nue to flow from the auxiliary tank A through the pathtraced including the high pressure cylinder 3 and into the low pressuretank 'creased from two cubic feet to four cubic lair pressure in thetank A will have oper and" discharges v tion with rapidity.

' B until the pressures in the tanks A and. B

'are equalized or forty pounds pressure 1n each tank. Inasmuch as thetanks are .of equal capacity, the volume will thus bey 1nfeet and thepressure correspondingly low- -ered from eighty pounds to forty' pounds.

The pressures in the auxiliary tanks., A and B having been equalizedacondition will he efectedas indicated in the opposite side or seriestanks A and B',` Fig. 1, which have .equal pressure of forty pounds persquare inch and which constitutes the second stage of operation, Fig. 3.At this mo- "ment the valves c and e will be closed andthe "valves ai,g, and h will be opened. Air` will then How simultaneously from bothcontainers A and B through the conduits 27 and 28 to the valves g` andit and thence through the conduits 19 and 20 to the inlet ports of thelow pressure cylinders/1 4 from which it is exhausted through theconduit 21 to atmosphere. At the sametimea charge of air is admittedthrough the conduits 14 and 13 to the valve a and thence A through theconduits 29 and 30 to the oppo- 7 site yside of the piston 23 in theauxiliary 105 tank B. This is the existing condition indicated on thelow pressure side or series Fig. 1 or in the second stage of'operationFig. 3. The pressure of the incoming air at supply tank pressure uponthe piston head drives the pistons in unison toward the right in Figs. 1and 3, causing the air to be discharged from the auxiliary tanks A andBsimultaneously at constant pressure of forty pounds each. s

It is to be noted that during the first stage l of operation While thetank A is discharg- Ying into the tank B the pressure gradually fallsfrom an initial pressure of eighty pounds per square inch toa `finalpressure of forty pounds per square inch at which time the auxiliarytanks A and B equalize.

During the second stage of operation while both tanks A and B aresimultaneously discharging through the low pressure 125 cylinders of themotor to atmosphere, there is nodrop or decrease of pressure inasmuch asa new high pressure charge is being admitted from the supply tank intothe auxiliary tank B on the opposite side ofthe pisanced by the pressureof forty pounds per s uare inch upon the opposite sides of each (i thepiston heads 22 and 23. The lncoming high pressure chargetherefore-causes the pistonsto move toward the. discharge'v ends of thetank. (see Figs. 3l and 4) ,to compensate for the discharged a1r andmaintains the operating pressure of both tanks constant until both areentirely exhausted. i

During this movement' of the piston the tank A is being supplied withair at atmospheric pressure at the rear side of the plston through theintake or breathing tube 25 whereby at the completion of the secondstage the relation of the auxiliary tanks A and B will be reversed andtank B will-con-` tain a high pressure charge vof eight lpounds persquare inch while tank A wil e at atmospheric pressure. The operationbefore described is then reversed and during the third stage representedb Fig. 4 the tank B is discharged through t e high pressure cylinder 3into tank A until they are equalized. Tank B having received its fullhlgh pressure charge, the valve a is closed and valves g and h whichcommunicate with the discharged or exhausted ends of thc auxiliary tanksA and B are also closed and the valves d and f are opened. The air uuderhigh pressure of eightly pounds per square inch is then discharged fromthe tank B through therconduits 30 and 31 to the valve el, then throughthe conduits 15 and 16 to the' high pressure cylinder 3' Jfrom which itis exhausted through the conduits 18 and 17 to the valve f and throughthe conduits 32 and 33 to the auxiliary tank A\ then at atmosphericpressure. The air will continue to How from the high pressure tank Bthrough the course last traced into the loW pressure tank A until thetanks A and B equalize With a pressure of forty pounds per square incheach.

At the beginning of the fourth and last stage of the cycle of operationsthe tanks are equalized as indicated in Fig. It will be remembered thatthe pistons at this point in the cycle of operation are at the right,Fig. 1, and the tank charges 'are at the left of the pistons and will bedischarged through the left hand endsof thc tanks. The valves (l and fare then closed and the valves 11,2', and j are opened. The charges ofair from both tanks A and B at forty pounds pressure are then dischargedsimultaneously through the conduits 30 and 33 to the valves j and vl andthen through the conduits 19 and'20 to the low pressure cyl.l

inders 4.-4 from which the air is exhausted through the conduit 21 toatmosphere.

At thel same time a high pressure charge is admitted from the supplytank 1 lthrough then through the'conduit 27 to the opposite side of thepiston head 22. This high pressure charge being admitted at an initialIthe conduits 14 and 13 to the valve b and pressure of eightly and fourtenths pounds' gradually decreasing to a final pressure of eighty poundsper square inch is counterbalanced by the opposing pressures of fortypounds per square lnch upon the opposite sides of both pistons causesthe pistons to `move toward the left to compensate for the discharge ofair from bothtanks at a constant pressure of forty pounds through thelow pressure cylinders 4--4 to atmosphere. The incoming high pressurecharge bymoving the piston to compensate for the discharge ofthe lowpressure charge maintains the 10W pressure charges constant at fortypounds pressure until both tanks are exhausted.

During this movement of the pistons air has been admitted to atmos hericpressure through the inlet or breathing tubeI 25 and past the checkvalve 26 into the auxiliary tank B to compensate for the movement of thepiston.

At the completion of the last or fourth stage the auxiliary tank A willcontain the high pressure charge of eighty pounds pressure while theauxiliary tank B Will be empty or at atmospheric pressure whichcompletes the cycle of operation, leaving the tanks in the conditionfound at the beginning of the first stage.

While the description thus far applies to one sideor series. only, thesame'description is equally applicable to the other side or series by.readingthe same reference characters with the prime marks .or exponentswhich distlnguish the characters and elements of one side or series fromthose ofthe other. The only difference between the operation of the twosides is that they operate in alternate relation, z'. e., *while thehigh pressure charge is being discharged from the auxiliary or variablepressure tank of one side through the high pressure cylinder 3 into thelow pressure tank of the same side the auxiliary or variable pressure 1soperating inthe second stage of the cycle and While the primary side orseries operates through the second stage of its cycle of operations, thesecondary side or series is operated through the third stage of itscycle of operations, "etc, Thus' While one slde or' series is supplyingthe high pressure cylinder 3 the other side orseries supplies the lowpressure cylinders 4 and both high and low pressure cylinders aresupplied alternately from opposite sides or series.

Each high .pressure charge is thus utilized first from initial highpressure'to half pres-- tank upon one side of the cistern throughthehigh pressure cylinder to the second tank upon the same side while atthe same time air at lower pressure is being supplied through the lowpressure cylinders simultaneously from both tanks upon the upper side ofthe cistern. The supply of air at `higher pressure continues through thehigh pressure cylinder until the `two tanks equalize whereupon the' airis switched from the equalizing tank simultaneously through the lowpressure cylinders through *atmosphere. vThus the high pressure cylinder3 receives air under high pressure from' the tank B and discharges itinto the tank .C until the tanks A and B equalize While at the same timethe cylinders 4 are receiving air simultaneously from the tanks A and B.By the time the low pressure tanks A have been exhausted on theirdischarge side vthey will have been recharged with high pressure supplyfrom the tank l through the lines 13 and valves a and b.' At this momentthe initial cylinders A and B will have Veolualized and the air supplywill have been switched from the high pressure cylinder 3 to the lowpressure cylinder-fi'whereby the tanks which supplied `the high pressurecylinder and vreceived the discharge thereq from will then supply thelow pressure cylinders and one of the tanks which had previouslysupplied the low pressure cylinders, will. now contain a charge at highpressure to supply the high pressure cylinder 3 which will dischargeinto the second or corresponding tank ofthe same side, until these tanksare equalized. Thus they alternate in operation. One tank dischargingthrough the high pressure cylinder into the other tank until these areequalized, and then both discharging through the low pressure cylindersto atmosphere until exi' hausted, during which time one of the tanks hasreceived a new high pressure charge. The opposite series of tanksbeing`engaged in the same cycle of operation but being differentlyvtimed.

lThe purpose or utility of the succession of tanks is to rela the airpressure through successions where it is twice used at differentpressure. n the first instance 1t 1s of high 'pressure and small bulkand in the second instance of increased bulk and low pressure.

As before stated, the supply tank and also each .of the auxiliary orvariable pressure tanksis insulated or jacketed to prevent so far as ispossible the loss of heat incident to compression. The compression ofthe air within the "supply tank will cause such air to be heated. Thisair in a heated condition is then admitted from the supply tank into theinitial auxilary or variable pressure tank and heats the walls thereof.The

air is then discharged from this primary heated tank into the secondtank of the same series or side. At the second succeeding stage, the airis discharged from the second tank which is then at high pressure, intothe low pressure tank previously heated by the high pressure chargewhich takes up a portion oi the heat from the walls of the tank orcontainer which tends to compensate for the expansion of air andtherebymaintain the air at even temperature or an isothermal condition.The expansion of the air in the previouslyrheated container or tank andits consequent absorption of heat from the walls thereof to maintain theeven or isothermal condition cools the tank somewhat preparatory toreceiving the succeeding high pressure heated charge which again heatsthe walls ofthe container. Thus the wallsor jacket of the tank orcontainer absorbs from the high pressure charge a quantity of heatthereby 100 lowering the temperature of the high pressure charge, whichabsorbed heat is given back to the low pressure charge subse quentlyreceived into the same tank or container thereby tending to raise thetempera- 10.5 ture of the low pressure charge to maintain the high andlow pressure charges at comparatively even temperature.

Valve operating` mechanism, compressors, and fluid pressure'motors arecommon and 111,

`well known in the art. Any suitable valve 'gear timed and arranged tooperate the valve in proper sequence and at proper in- 'structural.ifeatures, it is to be understood that the means and constructionherein descrlbed comprise but `one mode of putting sov the inventioninto effect and the invention is therefore claimed broadly in any of itspossible forms or modifications within the scqpe of the appended claims.

claim 1. In a fluid pressure system, ya supply' reservoir for fluidunder pressure, a motor, auxiliary reservoirs arranged in pairs,connecting conduits between the supply reserv'ir and the auxiliaryreservoirs, and be-A tween the auxiliary reservoirs and the motor, and avalve in each conduit, land means for automatically controlling saidvalve where'- b the fluid under pressure will b'e discliarged from thesupply reservoir into the initial auxi-liary reservoir, thence throughthe motor into the second auxiliary reservoir'of the pair, thencesimultaneously from both auxiliary reservoirs again through the motor toan area of low pressure or atmosphere.

2. In a fluid pressure system, a motor .having high and low pressuresections, two

reservoirs ofl substantially equal capacity,`

stantially. equal capacity, means for supplying fluid under pressure tosaid primary reservoir, conduits connecting the reservoirs and motor anda valve controlling each conduit, and means for automaticallycontrolling said valve whereby the fluid under pressure will bedischargld from the primary reservoir through t`e' high pressurecylinder into the secondary reservoir until the pressure of thereservoirs is substantially equal after which the fluid will besimultaneously discharged from both reservoirs through the low pressurecylinder of the motor.

4. In a fluid pressure system, a motor havling high and low pressurecylinders, two

pairs'of reservoirs and an independent series of valved conduitsconnecting each pair of reservoirs with the mot'or, means for supplyingfluid under pressure through said va ved conduits alternately to a resery voir of each pair and thence to the motor,

and means for opening and closing the valved conduits in sequence, theconstructionl and\ arrangement being such that the fluid aving thusdescribed my invention, I'

equal pressure, the fluid underpressure beingF simultaneously dischargedfrom both reservoirs of the second pair through the low pressurecylinder of the motor.

5. In a fluid pressure system, a source of supply for fluid undercompression, a utiliz- .ing mechanism having high and low pressuresections, two containers for fluid under pressure, a series of valvedconduits connecting each container with 4the source of supply and withthe utilizing mechanism and-through the utilizing mechanism` with theother container and with atmosphere and means for opening and closingthe valve conduits in predetermined sequence, inter.- connected pistonsin the' containers adapted to move in unison, the construction andarrangement being such that a charge of air or similar fluid beingadmitted at high pressure to one of the containers will be dischargedtherefrom through the high pressure section of the utilizing mechanisminto the second container, the increased, volume of fluid being thendischarged simultaneously from both containers through the low pressuresection of the utilizing mechanism' to normal or neutral pressure, and anew high pressure charge will be simultaneously admitted at the oppositeside of the piston into one of the containers 'to move said piston tocompensate for the'discharged fluid whereby the fluid remaining to bedischarged is maintained under constant pressure, and an inlet for airat atmosphericv pressure to each container to compensate for themovement of the piston therein.

6. In a fluid pressure system,'a source of supply for fluid underpressure, a fluid presf sure utilizing mechanism including high and lowpressure sections, two containersA for fluid under pressure, a piston ineach container, inter-connecting' means between the pistons whereby theywill move in unison,

means for admitting fluid under pressure to i one of said containers,means for equalizing the pressure in the containers by discharging aportion of the high pressure charge of fluid from Ythe said containerthrough the high pressure section of the utilizing mechanism into thesecond container whereby saidhigh pressure charge will assume increasedvolume at lower pressure, and

means for thereafter simultaneously discharging both containers throughthel low y pressure section of the utilizing mechanism, and means foradmitting a succeeding high pressurecharge to one of the containers atthe side of the piston opposite the contents being discharged wherebythe contents of both containers will be discharged at -substantiallyconstant pressure by the move the contents of said container through oneutilizing mechanism into the `second ,con-l tainer, means fordischarging the contents of both containers simultaneously throughanother utilizing mechanism, the high pressure charge being admitted tothe containers ,Y

alternately. c

8. In a fluid pressure system, a source of supply for fluid underpressure, a fluid pres- 4 sure utilizing mechanism including high andlow pressure sections, a plurality of containers for fluid underpressure, and a plurality of conduits connecting the containers with thesource of supply and with the utilizing mechanism, said containers and 4conduits being arranged intwo series or groups, means for admittingfluid under pressure alternately to a container of each series or group,the fluid under pressure be- I ing admitted alternately to thecontainers of the same sei/ies or group, means for alternatelydischarging a portion of the contents of t e charged container of eachseries or gro p through the high pressure section of the utilizingmechanism into a second container of the same series, means foralternately discharging the contents 'of the containers of each seriessimultaneously through the low pressure section of the utilizingmechanism, theh discharge of one container into another and bothcontainers simultaneously being effected alternately between therespective series or groups.

9.- The herein described method of utilizing air or similar fluid underpressure which consists in expanding the fluid from a high 'pressurecontainer through a utilizing mechanism into p a low pressure containerand then expanding the increased volume of iuid at lower pressuresimultaneously from both containers through another utilizing mechanismto normal or neutral pressure.`

In testimony whereof, I have hereunto set my hand this 27th day of JuneA. D. 1916.

GERGE H.. GROTH.

Witnesses:

HAnRrF. NoLAN, VAGamm: M. BECKER..

